| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a three-phase, four-wire distribution switchboard wherein a plug-in breaker having grooves into which a master bar is to be inserted in three tiers vertically arranged at one end can be used as a branch breaker and the material for four master bars are not wasted. <P>SOLUTION: Of the four master bars of the three-phase, four-wire distribution switchboard, the upper and intermediate bars 1, 2 are formed in a flat shape. The lower master bars 3, 4 are divided into right and left pieces and are formed so that the open end of each piece is substantially in an upside-down L shape. Plug-in breakers 5 having grooves 6 into which a master bar is to be inserted in three tiers vertically arranged at one end are plug-in connected from both sides. As a result, it is possible to make the sectional area of the lower master bars 3, 4 substantially equal to the sectional area of the upper and intermediate master bars 1, 2 and prevent the material for the master bars from being wasted. <P>COPYRIGHT: (C)2008,JPO&INPIT |
